Gun barrel with a breech piece screwed on an a-tube



Patented Apr. 11, 1922.

2 SHEETS-SHEET l- VULLMER. GUN BARREL WITH A BREECH PIECE SCREWED ON AN A-TUBE. APPLICATION FILED NOV. 19. 1920. 1,412,151.

Mm Q D EM W 1 m 1. VOLLMVERQ GUN BARREL WITH A BREECH PIECE SCREWED ON AN A-TUBE. APPLICATION FILED NOV. 19. 1920.

1,412,151. Patented Apr-11, 1922.

2 SHEETS-SHEET 2.

JOHN VOLLMER, ESSEN, GER-MANY, ASSIGNOB TU FRIED. KR-UPP AKTIENGESELL- SGHAET, ESSEI T-OIWTHE-R-UHB, GERZEANY.

GUN BARREL WITH A BREECI-I PIECE SCREWED ON All" A-TUBE.

raiaisi.

Speeificati :1 of LetterS'PatentQ Fatented Apr. 11, 1922;

Application fiiea November 19, 1920. Serial No. 425,106.

To all whom it may concern:

. Be it known that 1, JOHN VOLLMER, residing at Essen, Germany, a citizen of the Gernan Republic, have invented a certain new and useful TIDIIH'OVGYHQDt in Gun-Barrels with Breech Piece Screwed on an A-Tuloe,

parts in question of a constructional eXanp' ple of the invention,

Fig.2; is a section at-'22.in Fig. 1, seen from the left; Fig. 3 is the top plan view, partly in section,of Fig. 1;

(Fig. 4 is a longitudinal section of a second constructionalexample of the invention;

Fi 5 is a section at inFig. 4., seen 23 from the left; v

Fig. 6 is the top planview, partly'in section, of Fig. 4;

Fig. 7 is a section of a detail on a larger scale.

The gun-barrel shown in Figs. 1 to 3, which will be described first, consists of an A-tube A and a breech-piece B, the latter being formed with a .very short jacket portion 5 Which envelopes the rear portion of the A-tube. The breech-piece has on its underside a lug b for the attachment of the reoil-brake and the running-out gear. The connection between the A-tube and the breech-piece is obtained by means of screw threads (I 7J2. The portion 6 of'the breechpiece has cut on its front face a backward slope b '(Fig. 1), to which corresponds a front slope a cut on the rear face of a collar a formed on the A-tube. The two slopes a 72 together with the cylindrical surface of. the A-tube. enclose an annular groove of dovetailed cross section, in which two pairs of wedges C O are fitted in diametrically opposed positions. The wedges C C are curved concentrically with the axis of the bore. of the i i-tube; their length is about the groove a equal to one fourth of the circumference of.

a groove a. The sloped faces ofthewedges C C which bear against the faces a and b are cone surfaces, whereas the faces 0? (Fig. 3) by which the wedges bear against each other are helical surfaces perpendicular to the axis of the bore. The intervals remaining-in the groove a? between the two pairs of wedges are filled up by annular sectors D (Figs. 2 and 3) of rectangular cross section.- A ring E extending right up to the front face of the breech piece and which may be attached to the collar a by various means, for instance by fixing screws, overlies the wedges C C andthe pieces D.

After the breech-piece B has been screwed;

on the A-tube, the four wedges C C are placed in the annular groove a and keyed up pairwise. The wedges are retained in section and that of the groove a. Lastly, the filling pieces D are inserted in the intervals between the pairs of wedges, and the ring E 18 attached to the collar 0 0f the A-tube.

By means ofthe above described wedge arrangement it is possible to establish such a pressure in the screw connection a b as to ensure aperinanent rigid connection between the A tubeand the breech-piece, which can not be loosened, for instance, by the eccentric action of the resistance set up by the re coil brake and the running-out gear.

In the gun-barrel shown in Figs. 4 to 6, the jacket portion 6 of the breech-piece B is provided with an annular extension 6 having the same outside diameter as a collar a formed on the A-tube A. The collar a and the extension 6 are each provided, on their end surfaces facing each other, with six recesses a and 79 When the A-tube and breech-piece are correctly assembled, the walls of each pair of recesses a b enclose a cylindrical hollow space in which a cylindrical dowel F is inserted. The dowels F are made of soft (expansible) steel. Each dowel is perforated by an oval slot f (Figs. 6 and/7) extending from one endface (Fig. 7) to the other, the generatriX of the slot being parallel to the axis of the dowel. Into this slot is driven a double wedge formed by two wedges Gr G The dowels F and the wedges G G are retained in position by a ring H fixed in some way (for instance by shrinkage) over the collar (1 and by their own dovetailed cross the extension 6*. This modification is shown and claimed in application, N o. eSLOQS, filed June 28,1921.

After the breech'piece has been screwed on the Atube, the recesses a b are bored and the dowels F are placed in the recesses insuch manner that the oval slots f of some of the dowels assume the position shown on the drawing whereas the oval' slots of the remaining dowels are placed at right angles thereto. Then thewedges G G are inserted in the dowels F and driven tightly in,

thereby expanding the dowels'and rigidly connecting the A-tube and the breech-piece. Finally, the ring H is fixed over the collar ac and the extension Z2.

This alternate arrangement of the dowels F and wedges Gr G provides a reliable safeguard against the loosening of the breechpiece on the A-tube owing to the resistance set up by the recoil brake and the runningout gear, and also against the loosening of the A-tu'be in the breech-piece owing to the reaction of the rifling tending to rotate the A-tube. Further, the cylindrical sha e of the dowels F and the recesses a b facilitates the exact machining of the parts in question in the shops and ensures a uniform distribution of the pressure produced by the described Wedge arrangement.

Claims g g 1. A gun barrel comprising a breech-piece,

an A-tube; said breech-pieceand A-tube be ing in screw-threaded engagement with one another, tension devices interposed between the opposed faces of the A-tube and thebreech piece, and a ring surrounding-said tension devices. 7 a

2. A gun barrel comprising an A-tube a breech-piece, said A-tube and breech-piece having a screw-threaded engagement with one another, said A-tube and breech-piece having opposed faces shaped to form an an nular groove, pairs of wedges adapted to be positioned in said groove, and means for retaining said Wedges in place.

3. A gun barrel comprising an A-tube, a breech-piece, said A-tube and breech-piece having a screw-threaded engagement with one another; said A-tube and breech-piece being shaped to form an annular dovetailed groove, and wedges adapted to be positioned in said groove.

4-. A gun barrel comprising an A-tube, a breech-piece, said A-tube and breech-piece having a screw-threaded engagement with one another, the opposed faces of said A- tu'be and breech-piece being shaped to form an annular dove-tailed groove, pairs of wedges adapted to be positioned in said groove, the opposed faces of said wedges being perpendicular to the axis of the gun barrel. v p

5. A gun barrel comprising an A-tube, a breech-piece, said A-tube and breech-piece having a screw-threaded engagement with one another, the opposed faces of said A- tube and breech-piece being shaped to form an annular dove-tailed groove, two pair of wedges adapted to be inserted in said groove, filling pieces adapted to be positioned between the ends of said pairs of wedges and a ring surrounding said wedges and filling pieces for securing the same in place.

The foregoing specification signed at Essen, Germany, this 24th day of June, 1920.

' JOHN VOLLMER.

In presence of H S GoT'rsMANn, JOHANN DicKnRs. 

